Providing information relating to a document

ABSTRACT

A system identifies a document, performs a search to identify web documents relating to an attribute associated with the document, and provides information associated with the web documents and the document.

BACKGROUND

1. Field of the Invention

Systems and methods consistent with the principles of the invention relate generally to information retrieval and, more particularly, to the providing of information that is relevant to a particular document.

2. Description of Related Art

Modern computer networks, and in particular, the Internet, have made large bodies of information widely and easily available. Free Internet search engines, for instance, index many millions of web documents that are linked to the Internet. A user connected to the Internet can enter a simple search query to quickly locate web documents relevant to the search query.

One category of content that is not widely available on the Internet, however, includes the more traditional printed works of authorship, such as books and magazines. One impediment to making such works digitally available is that it can be difficult to convert printed versions of the works to digital form. Optical character recognition (OCR), which is the act of using an optical scanning device to generate images of text that are then converted to characters in a computer readable format (e.g., an ASCII file), is a known technique for converting printed text to a useful digital form. OCR systems generally include an optical scanner for generating images of printed pages and software for analyzing the images.

SUMMARY

According to one aspect, a method may include receiving a search query, performing a first search to identify a document based on the search query, performing a second search based on an attribute associated with the document, and presenting a result of the second search.

According to another aspect, a system may include a memory to store instructions and a processor to execute the instructions. The system may identify a document, perform a search to identify a web document with information relating to an attribute associated with the document, and present information associated with the web document.

According to yet another aspect, a graphical user interface embodied in a computer-readable medium may include a set of links to portions of a document, a description of the contents of the document, and bibliographic information associated with the document. The graphical user interface may also include a link to cause a search to be performed for a web document with information relating to an attribute associated with the document.

According to a further aspect, a method may include receiving identification of a document from a user, automatically performing a plurality of searches to identify web documents relating to attributes associated with the document, and providing information associated with the web documents to the user.

According to yet another aspect, a computer-readable medium may contain computer-executable instructions, including instructions for identifying a document, instructions for performing a search to identify web documents with information relating to an attribute associated with the document, instructions for extracting information from the web documents, and instructions for presenting the extracted information along with information associated with the document.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, explain the invention. In the drawings,

FIG. 1 is an exemplary diagram of a network in which systems and methods consistent with the principles of the invention may be implemented;

FIG. 2 is an exemplary diagram of a client or server of FIG. 1 according to an implementation consistent with the principles of the invention;

FIGS. 3A-3D are flowcharts of exemplary processing for presenting information regarding web documents related to a document according to some implementations consistent with the principles of the invention;

FIG. 4 is an exemplary diagram of a graphical user interface in which information associated with a document may be presented in the form of a search result according to one implementation consistent with the principles of the invention;

FIG. 5 is an exemplary diagram of presentation of a reference page associated with a document according to one implementation consistent with the principles of the invention;

FIG. 6 is an exemplary diagram of a graphical user interface in which information associated with web documents may be presented according to one implementation consistent with the principles of the invention;

FIG. 7 is an exemplary diagram of a portion of a reference page according to another implementation consistent with the principles of the invention;

FIG. 8 is an exemplary diagram of a portion of a reference page according to a further implementation consistent with the principles of the invention;

FIG. 9 is an exemplary diagram of a graphical user interface in which information associated with a document may be presented in the form of a search result according to an alternate implementation consistent with the principles of the invention; and

FIGS. 10A and 10B are exemplary diagrams of graphical user interfaces in which related information may be presented according to two different implementations consistent with the principles of the invention.

DETAILED DESCRIPTION

The following detailed description of the invention refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements. Also, the following detailed description does not limit the invention.

Overview

More and more types of documents are becoming searchable via search engines. For example, some documents, such as books, magazines, and/or catalogs, may be scanned and their text recognized via OCR. It is beneficial to understand more about these documents and make this additional information available to users.

Systems and methods consistent with the principles of the invention may automatically search for additional information relating to one or more attributes associated with a document (also referred to as “document attributes”) and provide this additional information in association with the document.

Exemplary Network Configuration

FIG. 1 is an exemplary diagram of a network 100 in which systems and methods consistent with the principles of the invention may be implemented. Network 100 may include multiple clients 110 connected to multiple servers 120-140 via a network 150. Two clients 110 and three servers 120-140 have been illustrated as connected to network 150 for simplicity. In practice, there may be more or fewer clients and servers. Also, in some instances, a client may perform the functions of a server and a server may perform the functions of a client.

Clients 110 may include client entities. An entity may be defined as a device, such as a wireless telephone, a personal computer, a personal digital assistant (PDA), a lap top, or another type of computation or communication device, a thread or process running on one of these devices, and/or an object executable by one of these devices. Servers 120-140 may include server entities that gather, process, search, and/or maintain documents in a manner consistent with the principles of the invention.

In an implementation consistent with the principles of the invention, server 120 may include a search engine 125 usable by clients 110. Server 120 may crawl a corpus of documents (e.g., web documents), index the documents, and store information associated with the documents in a repository of documents. Alternatively or additionally, server 120 may analyze a database (or set of databases) of documents (e.g., books, magazines, newspapers, articles, catalogs, etc.) and store information associated with the documents in the same or a different repository. Servers 130 and 140 may store or maintain documents that may be crawled or analyzed by server 120.

While servers 120-140 are shown as separate entities, it may be possible for one or more of servers 120-140 to perform one or more of the functions of another one or more of servers 120-140. For example, it may be possible that two or more of servers 120-140 are implemented as a single server. It may also be possible for a single one of servers 120-140 to be implemented as two or more separate (and possibly distributed) devices.

Network 150 may include a local area network (LAN), a wide area network (WAN), a telephone network, such as the Public Switched Telephone Network (PSTN), an intranet, the Internet, a memory device, or a combination of networks. Clients 110 and servers 120-140 may connect to network 150 via wired, wireless, and/or optical connections.

A “document,” as the term is used herein, is to be broadly interpreted to include any traditional printed work of authorship, such as books, magazines, catalogs, newspapers, articles, etc. A “web document,” as the term is used herein, is to be broadly interpreted to include any machine-readable and machine-storable work product available via a network, such as network 150. A web document may include, for example, a web site, a file, a combination of files, one or more files with embedded links to other files, a news group posting, a blog, a web advertisement, etc. In the context of the Internet, a common web document is a web page. Web pages often include textual information and may include embedded information (such as meta information, images, hyperlinks, etc.) and/or embedded instructions (such as Javascript, etc.). A “link,” as the term is used herein, is to be broadly interpreted to include any reference to or from a web document.

Exemplary Client/Server Architecture

FIG. 2 is an exemplary diagram of a client or server entity (hereinafter called “client/server entity”), which may correspond to one or more of clients 110 and servers 120-140, according to an implementation consistent with the principles of the invention. The client/server entity may include a bus 210, a processor 220, a main memory 230, a read only memory (ROM) 240, a storage device 250, an input device 260, an output device 270, and a communication interface 280. Bus 210 may include a path that permits communication among the elements of the client/server entity.

Processor 220 may include a conventional processor, microprocessor, or processing logic that interprets and executes instructions. Main memory 230 may include a random access memory (RAM) or another type of dynamic storage device that may store information and instructions for execution by processor 220. ROM 240 may include a conventional ROM device or another type of static storage device that may store static information and instructions for use by processor 220. Storage device 250 may include a magnetic and/or optical recording medium and its corresponding drive.

Input device 260 may include a conventional mechanism that permits an operator to input information to the client/server entity, such as a keyboard, a mouse, a pen, voice recognition and/or biometric mechanisms, etc. Output device 270 may include a conventional mechanism that outputs information to the operator, including a display, a printer, a speaker, etc. Communication interface 280 may include any transceiver-like mechanism that enables the client/server entity to communicate with other devices and/or systems. For example, communication interface 280 may include mechanisms for communicating with another device or system via a network, such as network 150.

As will be described in detail below, the client/server entity, consistent with the principles of the invention, may perform certain searching-related operations. The client/server entity may perform these operations in response to processor 220 executing software instructions contained in a computer-readable medium, such as memory 230. A computer-readable medium may be defined as a physical or logical memory device and/or carrier wave.

The software instructions may be read into memory 230 from another computer-readable medium, such as data storage device 250, or from another device via communication interface 280. The software instructions contained in memory 230 may cause processor 220 to perform processes that will be described later. Alternatively, hardwired circuitry may be used in place of or in combination with software instructions to implement processes consistent with the principles of the invention. Thus, implementations consistent with the principles of the invention are not limited to any specific combination of hardware circuitry and software.

Exemplary Processing

FIGS. 3A-3D are flowcharts of exemplary processing for presenting information regarding web documents related to a document according to some implementations consistent with the principles of the invention. Processing may begin with a user providing a search term (or a group of search terms) as a search query for searching a document repository. In one implementation, the document repository includes documents available from the Internet and/or a database (or set of databases) and the vehicle for searching this repository is a search engine, such as search engine 125 (FIG. 1). The user may provide the search query via web browser software on a client, such as client 110 (FIG. 1).

The search query may be received by the search engine and used to identify documents (e.g., books, magazines, newspapers, articles, catalogs, etc.) related to the search query (acts 305 and 310) (FIG. 3A). A number of techniques exist for identifying documents related to a search query. One such technique might include identifying documents that contain the search term or perhaps a synonym of the search term. When the search query includes more than one search term, then a technique might include identifying documents that contain the search terms as a phrase, that contain the search terms but not necessarily together, or that contain less than all of the search terms. Yet other techniques are known to those skilled in the art.

Optionally, the documents may be scored in some manner (act 315). For example, the score for a document may be based on an information retrieval (IR) score. Several techniques exist for generating an IR score. For example, an IR score for a document may be generated based on the number of occurrences of the search terms in the document text, where the search terms occur within the document (e.g., in a title, body, footer, header, etc.), or characteristics of occurrences of the search terms (e.g., font, size, color, etc.). Yet other techniques are known to those skilled in the art.

Search results may be formed based on the documents and their optional scores and presented to the user (act 320). In one implementation, the search results may include information associated with the documents, such as links to the documents, that may optionally be sorted based on the document scores. The search results may be provided as a HTML document, similar to search results provided by conventional search engines. Alternatively, the search results may be provided according to another format agreed-upon by the search engine and the client (e.g., Extensible Markup Language (XML)).

FIG. 4 is an exemplary diagram of a graphical user interface in which information associated with a document may be presented in the form of a search result 400 according to one implementation consistent with the principles of the invention. As shown in FIG. 4, search result 400 may include a document title 410, author information 420, an excerpt 430 from the document, and optionally a link 440 to other relevant excerpts in the document. Assume for this example, and the examples to follow, that a user has performed a search for documents relating to the search term “military” and one resulting document includes the “9/11 Report.”

Document title 410 may include the title associated with the document. Selection of document title 410 may cause detailed information associated with the document, possibly in the form of a reference page (described below) to be presented. Author information 420 may include the name(s) of the author(s) of the document. Excerpt 430 may include a portion of the document that includes a search term of the search query. Occurrences of the search term may be visually distinguished (e.g., highlighted) within excerpt 430. Link 440 may permit one or more other excerpts from the document that contain a search term to be presented to the user.

Returning to FIG. 3A, one of the documents in the search results may be selected by the user (act 325). Various well-known techniques may be used for selecting. For example, selection may be made by clicking, mousehover, mouseover, keyboard strike, etc. In one implementation, selection of a document may include selection of a link associated with the document, such as selection of document title 410 as shown in FIG. 4.

In one implementation consistent with the principles of the invention, detailed information regarding the document, possibly in the form of a reference page, may be presented to the user in response to the user selecting the document (act 330) (FIG. 3B). FIG. 5 is an exemplary diagram of a reference page 500 associated with a document according to one implementation consistent with the principles of the invention. As shown in FIG. 5, reference page 500 may include an excerpt 510 from the document, a synopsis 520 regarding the document, a jacket or flap description 530 associated with the document, related information 540, bibliographic information 550, and a set of links 560 to different portions of the document. In other implementations, reference page 500 may include more, fewer, or different types of information.

Excerpt 510 may include a portion of text from the document that may include a search term of the search query. The portion of text may correspond to an image of the document text or the text version. Occurrences of the search term may be visually distinguished (e.g., highlighted) in the portion of text. Synopsis 520 may include a brief description of the contents of the document. Jacket or flap description 530 may include text from a jacket, cover, or flap associated with the document.

Bibliographic information 550 may include information, such as the ISBN, ISSN, the name of the publisher, the category code that identifies a category of the topical content of the document, and/or the publication date. In other implementations, bibliographic information 550 may include more, fewer, or different pieces of information. Links 560 may include links to various portions of the document. For example, the links may reference the front cover, the table of contents, relevant excerpt(s), the index, and/or the back cover of the document. Selection of one of the links may cause an image of the corresponding document portion to be presented.

Related information 540 may include various types of information related to the document that a user might find useful. This information may be obtained by performing a search relating to a document attribute (e.g., title, author, category, publisher, publication date, etc.) to identify relevant web documents.

Examples of information that might be obtained by the search might include information associated with a review of the document, information associated with a topic of the document, information associated with a subject or category of the document, information associated with a book in the same series as the document, information associated with a magazine issue in the same magazine as the document, information associated with an article in the same journal, from the same conference, or in the same magazine as the document, information associated with a news article, blog, or another type of posting that refers to the document or an author of the document, information associated with a product relating to the document or a topic of the document, information associated with a publisher of the document, information associated with a publication date associated with the document, information associated with a biography of the author, information associated with a web document relating to the author, such as the author's web page, information associated with an image of the author, and/or information associated with other documents by the same author.

In one implementation, related information 540 may include a list of links associated with one or more document attributes. As shown in FIG. 5, two exemplary links 542 and 544 are shown. In practice, there may be additional links. Selection of one of the links may cause a search to be performed relating to a particular document attribute. For example, selection of the link associated with a biography of the author 544 may cause a search to be performed to identify a web document that includes information relating to a biography of the author of the document. Techniques for forming search queries relating to various topics are well known in the art.

Related information 540 may optionally also include a set of advertisements related to one or more of the document attributes 547. For example, an advertisement may offer for sale the document, a portion of the document, other documents associated with the author, or other documents relating to a same topic as the document. The set of advertisements 547 may also, or alternatively, be associated with or derived from other information, such as a term of a search query, another (e.g., related) document, or user behavior (e.g., searching or viewing history).

Returning to FIG. 3B, it may be determined whether information relating to a document attribute is desired (act 335). For example, it may be determined whether the user selected one of the links or an advertisement associated with related information 540. If information relating to a document attribute is desired, then a search may be performed relating to the document attribute to identify related web documents (act 340). For example, if the user desired information regarding a review of the document, a search may be performed using, for example, a word or words associated with the document's title or the author's name and a word like “review” or “reviews” as a search query. Techniques similar to ones described above may be used to identify web documents relevant to the search query.

The web documents may optionally be scored based on an IR score and/or a link-based score. Several techniques exist for generating IR and link-based scores. An exemplary technique for generating an IR score might be based on the number of occurrences of the search term in the document. An exemplary technique for generating a link-based score is described in U.S. Pat. No. 6,285,999. Yet other techniques are known to those skilled in the art.

In another implementation, searches may be performed for all of the links associated with related information 540 as background tasks. In other words, relevant web documents may be identified for the different types of information associated with related information 540 and these relevant web documents may be cached for later presentation to the user when the user indicates a desire for such information.

Search results may be formed based on the web documents and their optional scores and presented to the user (act 345). In one implementation, the search results may include information associated with the web documents, such as links to the web documents, that may optionally be sorted based on the web document scores. The search results may be provided as a HTML document, similar to search results provided by conventional search engines. Alternatively, the search results may be provided according to a format agreed upon by the search engine and the client (e.g., XML).

FIG. 6 is an exemplary diagram of a graphical user interface in which related information may be presented according to one implementation consistent with the principles of the invention. In this exemplary implementation, assume that the user desired additional information relating to a review of the document by selecting a corresponding link associated with related information 540. In this case, a search may be performed to identify web documents with reviews of the document. For example, search terms, such as a word or words associated with the document's title (e.g., “9/11 Report”) or the author's name and a word like “review” or “reviews” (or other search terms that are likely to identify web documents with reviews of the document), may be used to identify relevant web documents.

A set of search results, two examples of which are illustrated in FIG. 6, may be presented to the user. In FIG. 6, the exemplary search results correspond to reviews of a book—the 9/11 Report. Search result 600, for example, may include a web document identifier 610, an excerpt 620 from the web document, and other information 630 associated with the web document. Identifier 610 may identify the web document. Selection of identifier 610 may cause the web document to be presented. Excerpt 620 may include a portion of the web document that may include a search term of the search query. Occurrences of the search term may be visually distinguished (e.g., highlighted) in excerpt 620. Other information 630 may include an address of the web document, a size of the web document, a date associated with the web document, or other information associated with the web document.

In another implementation consistent with the principles of the invention, a search may be performed in response to the user selecting a document in the search results (act 325) (FIG. 3A). In this implementation, a search may be performed relating to one or more of the document attributes to identify related web documents (act 350) (FIG. 3C). For example, search queries may be formed for different document attributes and searches may be performed to identify relevant web documents. Techniques similar to ones described above may be used to identify and possibly score web documents relevant to a search query.

Detailed information regarding the document, including information regarding the relevant web documents, may be presented to the user, possibly in the form of a reference page (act 355). In one implementation, the reference page may resemble reference page 500 described above with regard to FIG. 5. In this implementation, however, the links associated with related information 540 may be replaced or supplemented with information associated with the relevant web documents.

FIG. 7 is an exemplary diagram of a portion of a reference page 700 according to another implementation consistent with the principles of the invention. In this implementation, a set of search results may be presented to the user relating to one or more document attributes. As shown in FIG. 7, two exemplary search results are presented corresponding to a review of the document 542. As also shown in FIG. 7, a link may be provided for additional search results.

Search result 710, for example, may include a web document source 712, an excerpt 714 from the web document, and other information 716 associated with the web document. Source 712 may include the source of the web document. Selection of source 712 may cause the corresponding web document to be presented. Excerpt 714 may include a portion of the web document that may include a search term of the search query. Occurrences of the search term may be visually distinguished (e.g., highlighted) in excerpt 714. Other information 716 may include an address of the web document, a size of the web document, a date associated with the web document, or other information associated with the web document.

In yet another implementation consistent with the principles of the invention, a search may be performed in response to the user selecting a document in the search results (act 325) (FIG. 3A). In this implementation, a search may be performed relating to one or more document attributes to identify related web documents (act 360) (FIG. 3D). For example, search queries may be formed for different document attributes and searches may be performed to identify relevant web documents. Techniques similar to ones described above may be used to identify and possibly score web documents relevant to a search query.

Information may be extracted from the relevant web documents (act 365). A page, possibly in the form of a reference page, may be created based on the extracted information and the page may be presented to the user (acts 370 and 375). In one implementation, the reference page may resemble reference page 500 described above with regard to FIG. 5. In this implementation, however, the links associated with related information 540 may be replaced or supplemented with the information extracted from the relevant web documents.

FIG. 8 is an exemplary diagram of a portion of a reference page 800 according to a further implementation consistent with the principles of the invention. In this implementation, information may be extracted from web document(s) corresponding to a set of search results and this information may be presented to the user for each type of related information 540. The particular types of information extracted from the search results may include any information that a user might find useful.

As shown in FIG. 8, information extracted from two exemplary search results are presented relating to a review of the document. Information 810, for example, may include information source 812, an optional customer rating 814, a review 816, and other information 818. Source 812 may include the source of the information (e.g., Amazon.com). Selection of source 812 may cause a web document from the source to be presented. Customer rating 814 may include a rating of the document by customers of source 812 (e.g., Amazon.com). Review 816 may include a review of the document (or a portion of the review) as provided by source 812 (e.g., Amazon.com). Other information 818 may include an address of the web document, a size of the web document, a date associated with the web document, or other information associated with the web document.

Alternate Graphical User Interfaces

In an alternate implementation consistent with the principles of the invention, information may be presented regarding a document similar to that described above with regard to FIG. 4. In this case, however, an additional link may be provided to related information similar to related information 540 (FIG. 5). FIG. 9 is an exemplary diagram of a graphical user interface in which information associated with a document may be presented in the form of a search result 900 according to this alternate implementation consistent with the principles of the invention. As shown in FIG. 9, search result 900 may include a document title 410, author information 420, an excerpt 430 from the document, an optional link 440 to other relevant excerpts in the document, and a link 910 to related information. Document title 410, author information 420, excerpt 430, and optional link 440 may be similar to those described above with regard to FIG. 4.

Link 910 may cause related information to be presented. FIGS. 10A and 10B are exemplary diagrams of graphical user interfaces in which related information may be presented according to two different implementations consistent with the principles of the invention. As shown in FIG. 10A, selection of link 910 may cause a set of links to be provided, which may optionally be separated based on the different types of document attributes with which they are associated. Selection of a link in the set of links may cause a search to be performed and results presented as described above.

As shown in FIG. 10B, selection of link 910 may cause a search to be performed and results to be presented with regard to the different types of document attributes with which they are associated. In one implementation, a set of search results may be provided (similar to FIG. 7). Selection of one of the search results may cause the corresponding web document to be presented as described above. In another implementation, information extracted from the web document(s) corresponding to a set of search results may be provided (similar to FIG. 8).

CONCLUSION

Systems and methods consistent with the principles of the invention may search for additional information relating to one or more document attributes and provide this additional information in association with the document.

The foregoing description of preferred embodiments of the present invention provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention.

For example, while series of acts have been described with regard to FIGS. 3A-3D, the order of the acts may be modified in other implementations consistent with the principles of the invention. Further, non-dependent acts may be performed in parallel.

It has been described that a document is identified as a result of a search and web documents related to the document or an author of the document may be presented. In other implementations, however, the document may be identified in other ways, such as from a directory, category, or other listing of documents.

Also, exemplary graphical user interfaces have been described with respect to FIGS. 4-10B. In other implementations consistent with the principles of the invention, the graphical user interfaces may include more, fewer, or different pieces of information.

It will be apparent to one of ordinary skill in the art that aspects of the invention, as described above, may be implemented in many different forms of software, firmware, and hardware in the implementations illustrated in the figures. The actual software code or specialized control hardware used to implement aspects consistent with the principles of the invention is not limiting of the present invention. Thus, the operation and behavior of the aspects were described without reference to the specific software code—it being understood that one of ordinary skill in the art would be able to design software and control hardware to implement the aspects based on the description herein.

No element, act, or instruction used in the present application should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Where only one item is intended, the term “one” or similar language is used. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. 

1-30. (canceled)
 31. A method comprising: receiving, by a computer system and from a client device, selection of a search result of a set of search results; presenting, by the computer system and for display on the client device, a reference page for a document associated with the selected search result, the reference page comprising a link, the link being associated with an attribute relating to the document; receiving, by the computer system and from the client device, selection of the link; performing, by the computer system and based on the received selection of the link, a search to identify documents based on the attribute relating to the document; and providing, by the computer system and based on the performed search, information relating to one or more of the identified documents for display on the client device as a second reference page associated with the document, the second reference page including a second link associated with an additional search relating to the attribute.
 32. The method of claim 31, where the reference page includes at least one of: a description of contents of the document; text associated with one of a jacket, a cover, or a flap associated with the document; bibliographic information associated with the document; or an advertisement.
 33. The method of claim 31, where the reference page includes: an excerpt from the document, and a set of links to portions of the document.
 34. The method of claim 33, where the set of links references at least one of: a front cover associated with the document, a table of contents associated with the document, an index associated with the document, or a back cover associated with the document.
 35. The method of claim 31, where the attribute corresponds to at least one of a title, an author, a category, a publisher, or a publication date associated with the document.
 36. The method of claim 31, where the providing information relating to the one or more of the identified documents for display on the client device as the second reference page comprises: generating scores for the identified documents; sorting the identified documents based on the generated scores; and presenting the sorted identified documents on the second reference page.
 37. The method of claim 36, where the generating the scores for the identified documents comprises: generating information retrieval scores for the identified documents; generating link-based scores for the identified documents; and generating overall scores for the identified documents based on the generated information retrieval scores and the generated link-based scores.
 38. A system comprising: one or more processors to: receive selection of a search result of a set of search results; present a reference page for a document associated with the selected search result, the reference page comprising a link, the link being associated with an attribute relating to the document; receive selection of the link; perform, based on the received selection of the link, a search to identify documents based on the attribute relating to the document; and provide, based on the performed search, information relating to one or more of the identified documents for display as a second reference page associated with the document, the second reference page including a second link associated with an additional search relating to the attribute.
 39. The system of claim 38, where the reference page includes at least one of: a description of contents of the document; text associated with one of a jacket, a cover, or a flap associated with the document; bibliographic information associated with the document; or an advertisement.
 40. The system of claim 38, where the reference page includes: an excerpt from the document, and a set of links to portions of the document.
 41. The system of claim 40, where the set of links references at least one of: a front cover associated with the document, a table of contents associated with the document, an index associated with the document, or a back cover associated with the document.
 42. The system of claim 38, where the attribute corresponds to at least one of a title, an author, a category, a publisher, or a publication date associated with the document.
 43. The system of claim 38, where, when providing information relating to the one or more of the identified documents for display as the second reference page, the one or more processors are further to: generate scores for the identified documents; sort the identified documents based on the generated scores; and present the sorted identified documents on the second reference page.
 44. The system of claim 43, where, when generating the scores for the identified documents, the one or more processors are further to: generate information retrieval scores for the identified documents; generate link-based scores for the identified documents; and generate overall scores for the identified documents based on the generated information retrieval scores and the generated link-based scores.
 45. A computer-readable medium storing instructions executable by one or more processors, the instructions comprising: one or more instructions that, when executed by the one or more processors, cause the one or more processors to: receive selection of a search result of a set of search results; present a reference page for a document associated with the selected search result, the reference page comprising a link, the link being associated with an attribute related to the document; receive selection of the link; perform, based on the received selection of the link, a search to identify documents based on the attribute related to the document; and provide, based on the performed search, information relating to one or more of the identified documents for display as a second reference page associated with the document, the second reference page including a second link associated with an additional search related to the attribute.
 46. The computer-readable medium of claim 45, where the reference page includes at least one of: a description of contents of the document; text associated with one of a jacket, a cover, or a flap associated with the document; bibliographic information associated with the document; or an advertisement.
 47. The computer-readable medium of claim 45, where the reference page includes: an excerpt from the document, and a set of links to portions of the document.
 48. The computer-readable medium of claim 47, where the set of links references at least one of: a front cover associated with the document, a table of contents associated with the document, an index associated with the document, or a back cover associated with the document.
 49. The computer-readable medium of claim 45, where the attribute corresponds to at least one of a title, an author, a category, a publisher, or a publication date associated with the document.
 50. The computer-readable medium of claim 45, where the one or more instructions to cause the one or more processors to provide information relating to the one or more of the identified documents for display as the second reference page comprise: one or more instructions to cause the one or more processors to: generate scores for the identified documents; sort the identified documents based on the generated scores; and present the sorted identified documents on the second reference page. 